chore: add postgres version to matrix

.github/workflows/testing.yml

@@ -13,15 +13,19 @@ jobs:
  strategy:
  fail-fast: true
  matrix:
- version:
- - 20
- name: test and build package (node ${{ matrix.version }})
+ node:
+ version:
+ - 20
+ postgres:
+ version:
+ - 13
+ name: test and build package (node ${{ matrix.node.version }})
  runs-on: ubuntu-latest
- container: node:${{ matrix.version }}-alpine
+ container: node:${{ matrix.node.version }}-alpine
 
  services:
  postgres: # Label used to access the service container
- image: postgres:13-alpine
+ image: postgres:${{ matrix.postgres.version }}-alpine
  env:
  POSTGRES_DB: postgres
  POSTGRES_USER: postgres